WATCH: Obama Denounces Trump’s Wall In Rutgers Commencement Address

He told a crowd of more than 50,000 that the world is becoming more connected and “building walls won’t change that.”

Without uttering Donald Trump‘s name, President Barack Obama on Sunday condemned the Republican presidential front-runner’s proposal to build a wall along the nation’s southern border while delivering the Rutgers University commencement address in Piscataway, New Jersey, reports the Washington Post.

The president, speaking to a crowd of more than 50,000 in the school’s football stadium, said the world is becoming ever more interconnected and “building walls won’t change that,” the report says:

The 45-minute-long address was filled with obvious jabs at presumptive Republican nominee Donald Trump, whom the president didn’t name but who was a foil for the speech’s most cutting applause lines.

Obama slammed Trump’s proposal to build a wall along the country’s southern border, saying the world is becoming ever more interconnected and “building walls won’t change that.”

He mocked Trump’s call to “Make America Great Again,” saying that there was never a better time to be alive on the planet and in America. College graduation rates are up, he said. Crime rates have dropped, and more women are in the workplace than ever before in the country’s history.

He told graduates to take it with a grain of salt “when you hear someone longing for the good old days.”